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Carlos Chiossone
09-15-2006, 7:56 PM
Can some of you experts post some tips on how to avid burning edges. While most of my work will be with wood, and I don't mind the burnt as much, some will be on paper. I demo a ULS M-300 today and was getting burnt edges.

Thanks,
Carlos

Dave Fifield
09-15-2006, 8:06 PM
More power, faster cutting speed, lower pulse rate....and it doesn't hurt to use laser mask (app tape) to stop the burning from breeching the edges.

How thick a piece of wood were you trying to cut? What speed/power/pulserate settings did you have on the laser, and what power is the laser?

:Dave F.

Mike Mackenzie
09-15-2006, 8:13 PM
Carlos,

You will always get some burning however you can eliminate 90% by using a ppi setting of 150-200. We can cut white paper with this setting and get no burn on the edge.

Carlos Chiossone
09-15-2006, 8:15 PM
How thick a piece of wood were you trying to cut? What speed/power/pulserate settings did you have on the laser, and what power is the laser?

I used 2 types:
one was basswood 0.38 inch thick. Using a 30W at 100% power 5% speed with 5 passes to cut completely.
the second one was Granadillo (cocobolo) very dense at 0.21 inch. Same 100% power and 5% speed.

No idea what the pulserate was, I was demoing the machine, very new to this.

You mentioned tape, is this for the wood or the paper? I am very interested.

Thanks,
Carlos

Dave Fifield
09-15-2006, 10:10 PM
Carols,

The basswood should cut clean fairly easily, but I'm not sure about cocobolo, that's a very dense and oily wood - you might not be able to cut it without scorching the edges.

The printer driver software for the laser should have a setting for pulses per inch or pulse per second or pulse repitiion rate (PPI, PPS, PRR). I'm not aware which the ULS laser uses, but you need to look for this setting in the driver and make sure it's set fairly low for cutting 3/8" thick wood!

For a 30W laser, cutting 3/8" of basswood, I would set it to go at 3% speed, 100% power and a pulserate of 200. If the test/demo you did had it set to default (usually around 2500), then the edges would be well blackened IMO.

Laser tape, or App Tape as some call it, is just a thin paper tape with sticky glue on one side (not too sticky though - a bit like a 3M post-it note sticky). It's a bit like wide masking tape. You can get it from multiple sources. Try http://www.signwarehouse.com/c-application-tape.html or http://www.laserbits.com/. You stick it on wood or acrylic typically. Not sure how it would work on paper - the glue might be too sticky....

This stuff is great if you want to engrave nameplates and similar. You stick the tape over the face (or both faces if you are using it to prevent smoke/resin/burn damage to the faces) of the work, then engrave away, then fill the engraved areas with paint (gold is my fave) and then remove the tape carefully just before it drys hard. Looks fabulous.

Hope this helps.

:Dave F.

Carlos Chiossone
09-16-2006, 11:24 AM
Thanks for the tips on the machine, I will definately try it when I get the machine in.

But the tape answer made my day. I use something very similar to it when masking and painting. And have it here by the tons, I tested it on paper and it does not rip it off, excellent idea.

Thanks agin,
Carlos